Cleaning method of apparatus for manufacturing semiconductor device

ABSTRACT

A cleaning method of an apparatus for manufacturing a semiconductor device includes providing a first cleaning gas and a second cleaning gas into a chamber, and forming a mixture of the first cleaning gas and the second cleaning gas, wherein the first cleaning gas includes a fluorocarbon gas and an oxygen gas and the second cleaning gas includes nitrogen, activating the mixture of the first cleaning gas and the second cleaning gas by a high frequency power, and exhausting residues cleaned by the activated mixture and remaining gases.

[0001] The present invention claims the benefit of Korean PatentApplication No. 2003-05789, filed in Korea on Jan. 29, 2003, which ishereby incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a cleaning method of anapparatus for manufacturing a semiconductor device, and moreparticularly, to a cleaning method of an apparatus for depositing thinfilms.

[0004] 2. Discussion of the Related Art

[0005] Thin films of a semiconductor device are formed by variousmethods including a chemical vapor deposition (CVD) method. Afterdepositing each thin film, a chamber of a deposition apparatus iscleaned so as to remove source gases and residual products remaining onan inner wall of the chamber and in the chamber.

[0006] Perfluorocompound (PFC) gases, such as CF₄, C₂F₆, C₃F₈, C₄F₈, andSF₆, may be used as gases for removing silicon, silicon oxide (SiO_(X))or silicon nitride (SiN_(X)) existing in the chamber. However, in thecase of cleaning the chamber by using the PFC gases, global warminggases may be exhausted because the PFC gases may have low efficiency andmay be recombined in an outlet of the chamber. The global warming gasesabsorb infrared (IR) rays and cause global warming. Thus, in cleaningthe camber for the deposition apparatus, several methods, which usegases substituting the PFC gases or reduce quantity of the globalwarming gases while using the PFC gases, have been proposed.

[0007] Recently, NF₃ is widely used as a cleaning gas substituting thePFC gases, and NF₃ has a high cleaning rate and discharge extremelysmall quantities of the global warming gases. By the way, since NF₃ isformed through complicated processes, NF₃ is short of supply. Therefore,NF₃ is provided at a high price, and raise a manufacturing cost. Inaddition, when the chamber for the deposition apparatus is cleaned usingNF₃, poisonous fluorine gas (F₂) may be formed as a residual product. F₂corrodes the inner surfaces of the chamber during cleaning, and thus theapparatus for manufacturing the semiconductor device may be damaged.

[0008] Other cleaning gases have been suggested, but the cleaning gaseshave lower cleaning rates as compared with NF₃.

SUMMARY OF THE INVENTION

[0009] Accordingly, the present invention is directed to a cleaningmethod of an apparatus for manufacturing a semiconductor device thatsubstantially obviates one or more of problems due to limitations anddisadvantages of the related art.

[0010] An advantage of the present invention is to provide a cleaningmethod of an apparatus for manufacturing a semiconductor device thatprevents global warming.

[0011] Another advantage of the present invention is to provide acleaning method of an apparatus for manufacturing a semiconductor devicethat reduces global warming gases released after cleaning the apparatus.

[0012] Another advantage of the present invention is to provide acleaning method of an apparatus for manufacturing a semiconductor devicethat increases cleaning rates and improves efficiency of processing.

[0013] An advantage of the present invention is to provide a cleaningmethod of an apparatus for manufacturing a semiconductor device thatcleans uniformly the inner side of a chamber of the apparatus.

[0014] Additional features and advantages of the invention will be setforth in the description which follows, and in part will be apparentfrom the description, or may be learned by practice of the invention.The objectives and other advantages of the invention will be realizedand attained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

[0015] To achieve these and other advantages and in accordance with thepurpose of the present invention, as embodied and broadly described, acleaning method of an apparatus for manufacturing a semiconductor deviceincludes providing a first cleaning gas and a second cleaning gas into achamber, and forming a mixture of the first cleaning gas and the secondcleaning gas, wherein the first cleaning gas includes a fluorocarbon gasand an oxygen gas and the second cleaning gas includes nitrogen,activating the mixture of the first cleaning gas and the second cleaninggas by a high frequency power, and exhausting residues cleaned by theactivated mixture and remaining gases.

[0016] In another aspect of the present invention, a cleaning method ofan apparatus for manufacturing a semiconductor device includesactivating a first cleaning gas by a high frequency power, wherein thefirst cleaning gas includes a fluorocarbon gas and an oxygen gas,activating a second cleaning gas by a high frequency power, wherein thesecond cleaning gas includes nitrogen, mixing the activated firstcleaning gas and the activated second cleaning gas, thereby forming amixture of the first cleaning gas and the second cleaning gas, andexhausting residues cleaned by the mixtuer and remaining gases.

[0017] It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory and are intended to provide further explanation of theinvention as claimed.

BRIEF DESCRIPTION OF THE DRAWING

[0018] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this specification, illustrate embodiments of theinvention and together with the description serve to explain theprinciples of the invention.

[0019] In the drawings:

[0020]FIG. 1 is a schematic view showing an apparatus for manufacturinga semiconductor device used in the cleaning method according to a firstembodiment of the present invention; and

[0021]FIG. 2 is a schematic view showing an apparatus for manufacturinga semiconductor device used in the cleaning method according to a fourthembodiment of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0022] Reference will now be made in detail to the illustratedembodiments of the present invention, the examples of which areillustrated in the accompanying drawings.

[0023] In the present invention, a first cleaning gas and a second gasare used to clean a chamber for a deposition apparatus. The firstcleaning gas includes a fluorocarbon gas and an oxygen gas and thesecond cleaning gas includes nitrogen. The second cleaning gas issupplied at a regular rate to the first cleaning gas.

[0024] The fluorocarbon gas, beneficially, may be one of C₃F₈, C₄F₈ andC₄F₈O. The fluorocarbon gas is activated to F radical by plasma, and isexhausted by reacting silicon in silicon, silicon nitride or siliconoxide remaining in the chamber and forming SiF₄. Therefore, the cleaningprocess is performed.

[0025] The oxygen gas diffuses the fluorocarbon gas and the secondcleaning gas including nitrogen. Additionally, the oxygen gas preventsthe fluorocarbon gas from being a polymer such as (CF₂)_(n) and improvesa cleaning rate by oxidizing residues in the chamber.

[0026] The fluorocarbon gas and the oxygen gas are supplied into thechamber or into a plasma generating system, which may be independentlydisposed outside the chamber, thereby forming the first cleaning gas ofthe present invention. The cleaning rate may increase with the additionof the fluorocarbon gas and the oxygen gas, and global warming gasesreleased during the cleaning process are also increased. Thus, Thefluorocarbon gas and the oxygen gas should be provided at an appropriaterate.

[0027] The oxygen gas should be more than the fluorocarbon gas, andbeneficially, the flow rate of the fluorocarbon gas to the oxygen gasmay be 0.1 to 0.5. If the fluorocarbon gas is supplied less than theabove flow rate, it is hard to obtain expected cleaning effect. If thefluorocarbon gas is supplied more than the above flow rate, a propercleaning efficiency to the increased flow cannot be achieved because theremaining time in the chamber decreases due to the increased flow.

[0028] On the other hand, as stated above, the cleaning gas of thepresent invention includes the second cleaning gas having nitrogen. Thesecond cleaning gas is supplied to have a flow rate of about 0.01 to 0.5to the first cleaning gas. If the second cleaning gas is supplied lessthan the above flow rate, the cleaning effect cannot be expected, and ifthe second cleaning gas is supplied more than the above flow rate, thecleaning rate and the decrease of the global warming effect are noteffective for the increased flow rate.

[0029] The second cleaning gas may be selected from one of N₂, NO andN₂O. The second cleaning gas is activated to NO or NO radical by plasma,and removes nitrogen or oxygen on a surface of a film remaining in thechamber as shown in the following reaction formulas (1) to (4), therebyaccelerating reaction between silicon on the surface of the film, wherenitrogen or oxygen is removed, and F radical, which is formed bydissociating the fluorocarbon gas.

NO+Si—N(s)→Si(s)+N₂O  (1)

N+O→NO  (2)

NO+Si—O(s)→Si(s)+NO₂  (3)

NO₂+O→NO+O₂  (4)

[0030] In addition, the oxygen gas in the first cleaning gas and thesecond cleaning gas lower global warming potentials of gases emittedduring the cleaning process. The fluorocarbon gas of the presentinvention may be recombined during the cleaning process, and forms CF₄,C₂F₆, C₃F₈, C₄F₈, COF₂, SiF₄, HF, and so on.

[0031] Among the above gases including fluorine, carbon tetrafluoride(CF₄), which has a high global warming potential, reacts O radicaldissociated from the oxygen gas by plasma, and is changed to a gashaving a low global warming potential, such as CO_(x) or COF_(x). Or CF₄reacts N radical dissociated from the second cleaning gas, and ischanged to CN or NF_(x) having a low global warming potential.Therefore, the cleaning gas of the present invention reduces the globalwarming effect due to PFC gases formed during the cleaning process ofthe chamber.

[0032] Destruction of feed gas and the effect of emitted gases on globalwarming are quantified as destructive removal efficiencies (DREs) andmillion metric tons of carbon equivalents (MMTCEs), respectively. DREand MMTCE values are calculated by using the following equations (1) and(2), respectively;

DRE(%)=[1−C _(o) /C _(i)]×100,  equation (1)

[0033] where C_(i) is the gas volumetric concentration before the plasmacleaning and C_(o) is the gas volumetric concentration after the plasmacleaning, and

MMTCE=Σ12/44×{Q(kg)×GWP/10⁹},  equation (2)

[0034] where Q is the total mass of gases (in Kg) released during thecleaning process, and GWP is the global warming potential of eachcomponent (integrated over a 100 year time horizon).

[0035] Exemplary embodiments will be explained hereinafter withreference to attached drawings.

[0036] First Embodiment

[0037]FIG. 1 shows a schematic view of an apparatus for manufacturing asemiconductor device used in the cleaning method according to a firstembodiment of the present invention. In the first embodiment of thepresent invention, a remote plasma generator 70 outside a chamber 10 isused to activate cleaning gases. One part of the remote plasma generator70 is connected to a radio frequency (RF) power supply 20, and the otherpart of the remote plasma generator 70 is grounded. A gas inlet (notshown) is connected to the remote plasma generator 70. Plasma formed inthe remote plasma generator 70 flows in the chamber 10 through a plasmainlet 31. A substrate holder 16 is disposed in the chamber 10, and anexhaust line 32 is connected to the chamber 10 to exhaust cleaningresidues. The exhaust line 32 is also connected to a booster pump 34 anda dry pump 36, and a control valve 40 is located in the exhaust line 32.The pressure in the chamber 10 can be regulated by the control valve 40.Nitrogen gas (N₂) is used as a purging gas of the dry pump 36, and aflow rate of N₂ is uniformly maintained during a cleaning process. Theremote plasma generator 70 may use a remote inductively couple plasma(ICP) source.

[0038] A cleaning rate of the chamber 10 is measured by astep-profilermeter 50, and a Fourier transform Infrared (FT-IR)spectrometer 60 is equipped at one end of the exhaust line 32 to measurethe MMTCE of the PFC gases released during the cleaning process.

[0039] The remote plasma generator 70 uses 13.56 MHz as a RF power.During the cleaning process, RF power applied to the remote plasmagenerator 70 is about 500 Watts and the pressure in the chamber 10 isabout 300 mTorr. Silicon nitride (not shown) is used as samples formeasuring the cleaning rates of the chamber 10, and the samples arelocated at the center of the substrate holder 16, at the side wall ofthe chamber 10, and at the front wall of the chamber 10, respectively.

[0040] C₄F₈ is used as the fluorocarbon gas of the first cleaning gas,and N₂O is used as the second cleaning gas. C₄F₈ of about 20 sccm and O₂of about 140 sccm are supplied into the remote plasma generator 70,because the highest cleaning rate for the silicon nitride is obtained atC₄F₈(20 sccm)/O₂(140 sccm). The cleaning rate of C₄F₈/O₂ without thesecond cleaning gas is about 110 nm/min.

[0041] N₂O, as the second cleaning gas, is supplied at rates of about0.05 to about 0.20 to the total flow of the first cleaning gas, whereinthe total flow of the first cleaning gas is 160 sccm, and the cleaningrate, the DRE and the MMTCE are measured at each flow rate.

[0042] The addition of N₂O to the first cleaning gas, C₄F₈/O₂, up to therate of about 0.05, increases the cleaning rate, and the highestcleaning rate is about 300 nm/min at the rate of about 0.05. Furtheradditions of N₂O do not particularly change the cleaning rates ascompared with the cleaning rate at 0.05 N₂₀.

[0043] There are differences in the cleaning rates at the center of thesubstrate holder 16, at the side wall of the chamber 10, and at thefront wall of the chamber 10, and the differences in the cleaning ratesare less than about 10%, thereby showing uniform cleaning rates.

[0044] The DREs of C₄F₈ with N₂O are higher than 99%, and thus it isunderstood that almost all of supplied C₄F₈ is destructed during thecleaning process.

[0045] The PFC gases emitted during the cleaning process are measuredfor about 2 minutes, and the MMTCEs of the PFC gases decrease until theaddition of N₂O to C₄F₈/O₂ is 0.15. Therefore, the additions of N₂O toC₄F₈/O₂ are effective in controlling the global warming effect.

[0046] Meanwhile, the MMTCEs of the PFC gases emitted while cleaning thesilicon nitride of about 1,000 nm are calculated. When N₂O is not addedto the first cleaning gas, the MMTCE is about 1.3×10⁻⁹. When the flowrate of N₂O to the first cleaning gas is about 0.05, the MMTCE decreaseby about 75% as compared with the MMTCE of the case without N₂O, and isabout 3.5×10⁻¹⁰. When the flow rate of N₂O to the first cleaning gas isabout 0.2, the MMTCE is about 5.0×10⁻¹⁰.

[0047] Second Embodiment

[0048] In a second embodiment, RF power of about 800 Watts forgenerating plasma is applied to the remote plasma generator 70 of FIG.1, and the pressure in the chamber 10 of FIG. 1 is about 400 mTorr.Other conditions of the second embodiment are the same as conditions ofthe first embodiment, and the same apparatus in the first embodiment maybe used. In addition, samples for measuring cleaning rates of thechamber are located at the center of the substrate holder 16, at theside wall of the chamber 10, and at the front wall of the chamber 10,respectively.

[0049] C₄F₈O is used as the fluorocarbon gas of the first cleaning gas,and N₂O or NO is used as the second cleaning gas. C₄F₈O of about 40 sccmand O₂ of about 180 sccm are supplied into the remote plasma generator70. When the second cleaning gas is not supplied, the cleaning rate isabout 118 nm/min, and the DRE and the MMTCE are about 96% and about7.023×10⁻¹⁰ respectively.

[0050] N₂O or NO, as the second cleaning gas, is supplied at rates ofabout 0.05 to about 0.25 to the total flow of the first cleaning gas,respectively, wherein the total flow of the first cleaning gas is 220sccm, and the cleaning rate, the DRE and the MMTCE are measured at eachflow rate of each second cleaning gas.

[0051] In the case that the second cleaning gas is N₂O, the additions ofN₂O to the first cleaning gas, C₄F₈O/O₂, increase the cleaning rates,and the cleaning rate is about 1,190 nm/min at the flow rate of about0.15. Further additions of N₂O do not particularly change the cleaningrates as compared with the cleaning rate at 0.15 of N₂O to the firstcleaning gas. The differences in the cleaning rates at the threelocations are about 13%. The DREs of C₄F₈O are higher than 96% withoutregard to additions of N₂O. The MMTCE at the addition of 0.05 N₂O toC₄F₈O/O₂ decreases by about 95%. Therefore, the additions of N₂O toC₄F₈O/O₂ are effective in controlling the global warming effect.

[0052] When NO is added as the second cleaning gas to C₄F₈O/O₂, thecleaning rate increases, and is about 1,150 nm/min at the flow rate of0.05 NO to C₄F₈O/O₂. Although NO is added over 0.05 of the flow rate,the cleaning rates are about the same value as the cleaning rate at 0.05of NO to the first cleaning gas. The differences in the cleaning ratesat the three locations are about 11%, and the cleaning is uniform at thethree locations. The DREs of C₄F₈O are similar without regard toadditions of NO. The MMTCE at the addition of 0.05 NO to C₄F₈O/O₂decreases by 93% as compared with the MMTCE when NO is not added.

[0053] Third Embodiment

[0054] In a third embodiment, RF power for generating plasma is about300 Watts and the pressure in the chamber is about 400 mTorr. The thirdembodiment may use a capacitively coupled plasma (CCP) system.

[0055] Silicon nitride (5 cm×5 cm) formed on a silicon wafer is used assamples for measuring the cleaning rates of the chamber. C₄F₈O is usedas the fluorocarbon gas of the first cleaning gas, and N₂ is used as thesecond cleaning gas. C₄F₈O of about 16 sccm and O₂ of about 64 sccm aresupplied into the chamber. When the second cleaning gas is not supplied,the cleaning rate is about 507.7 nm/min, and the DRE and the MMTCE areabout 98.38% and 3.58×10⁻⁹, respectively.

[0056] N₂ is supplied as the second cleaning gas at rates of about 0.05to about 0.20 to the total flow of the first cleaning gas, respectively,wherein the total flow of the first cleaning gas is 80 sccm, and thecleaning rate, the DRE and the MMTCE are measured at each flow rate.

[0057] The additions of N₂ to the first cleaning gas, C₄F₈O/O₂, increasethe cleaning rates, and the cleaning rate is highest at the flow rate of0.10 of N₂ to C₄F₈O/O₂. The cleaning rate at 0.10 of N₂ to C₄F₈O/O₂increases by about 32.5% as compared with the cleaning rate when N₂ isnot added. Although N₂ is added over the flow rate of 0.10, the cleaningrates are about the same value as the cleaning rate at 0.10 of N₂ to thefirst cleaning gas.

[0058] The DREs of C₄F₈O are higher than 97% while N₂ is added at theflow rates of 0.05 to 0.20 to C₄F₈O/O₂. The MMTCE at the addition of0.10 of N₂ to C₄F₈O/O₂ decreases by about 38.0% as compared with theMMTCE the cleaning gas without N₂.

[0059] Fourth Embodiment

[0060]FIG. 2 shows a schematic view of an apparatus for manufacturing asemiconductor device used in the cleaning method according to a fourthembodiment of the present invention.

[0061] In FIG. 2, an upper electrode 12 and a lower electrode 14 aredisposed in a chamber 10. The upper electrode 12 is connected to a radiofrequency (RF) power supply 20 and the lower electrode 14 is grounded. Agas inlet 30 is equipped at the chamber 10, and a substrate holder 16 isdisposed in the chamber 10. An exhaust line 32 is connected to thechamber 10 to exhaust cleaning residues. The exhaust line 32 is alsoconnected to a booster pump 34 and a dry pump 36, and a control valve 40is located in the exhaust line 32. The pressure in the chamber 10 can beregulated by the control valve 40. Nitrogen gas (N₂) is used as apurging gas of the dry pump 36, and a flow rate of N₂ is uniformlymaintained during a cleaning process. A cleaning rate of the chamber 10is measured by a step-profilermeter 50, and a Fourier transform Infrared(FT-IR) spectrometer 60 is equipped at one end of the exhaust line 32 tomeasure the MMTCE of the PFC gases released during the cleaning process.Samples for measuring the cleaning rates are located on the substrateholder.

[0062] The fourth embodiment of the present invention may use acapacitively coupled plasma (CCP) system for generating plasma. RF powerof about 350 Watts is supplied and the pressure in the chamber is about500 mTorr during the cleaning.

[0063] C₄F₈O is used as the fluorocarbon gas of the first cleaning gas,and N₂O or NO is used as the second cleaning gas. C₄F₈O of about 16 sccmand O₂ of about 64 sccm are supplied into the chamber 10. When thesecond cleaning gas is not supplied, the cleaning rate is about 600nm/min, and the DRE and the MMTCE are about 98% and about 3.6×10⁻¹⁰,respectively.

[0064] N₂O or NO, as the second cleaning gas, is supplied at rates ofabout 0.05 to about 0.25 to the total flow of the first cleaning gas,respectively, wherein the total flow of the first cleaning gas is 80sccm, and the cleaning rate, the DRE and the MMTCE are measured at eachflow rate of each second cleaning gas.

[0065] The cleaning rates are increased as N₂O or NO are added to thefirst cleaning gas, C₄F₈O/O₂, and particularly at flow rates of 0.05 to0.15 to the first cleaning gas. The cleaning rates at additions of NOare higher than those at additions of N₂O.

[0066] The DREs are within a range of about 95% to about 99% withoutregard to additions and kinds of the second cleaning gas. The additionsof the second cleaning gas to C₄F₈₀/O₂ decrease the MMTCEs. The MMTCEnormalized to 1,000 nm/min of the cleaning rate for silicon nitride isabout 5.66×10⁻¹⁰ when the second cleaning rate is not added. Thenormalized MMTCEs decrease with the additions of the second cleaninggases to the first cleaning gas, and are about 2.52×10⁻¹⁰ at 0.15 of NOand 3.31×10⁻¹⁰ at 0.15 of N₂O, respectively.

[0067] Fifth Embodiment

[0068] C₃F₈ is used as the fluorocarbon gas of the first cleaning gas,and N₂, NO, or N₂O is used as the second cleaning gas. C₃F₈ of about 150sccm and O₂ of about 350 sccm are supplied. When the second cleaning gasis not added, the cleaning rate is about 258.9 nm/min, and the DRE andthe MMTCE are about 99% and about 1.4×10⁻¹⁰, respectively.

[0069] In the case of N₂, the cleaning rate is highest at the additionof 0.10 N₂ to C₃F₈/O₂, and is about 304.3 nm/min. In the case of NO, thecleaning rate is highest at the addition of 0.05 NO to C₃F₈/O₂, and isabout 433 nm/min. In the case of N₂O, the cleaning rate is highest atthe addition of 0.10 N₂O to C₃F₈/O₂, and is about 426.5 nm/min.

[0070] The DREs are about 99% without regard to additions and kinds ofthe second cleaning gas.

[0071] The additions of the second cleaning gases, N₂, NO and N₂O, toC₃F₈/O₂ decrease the MMTCEs. The MMTCEs are rapidly decreased when theflow rate of the second cleaning gas to the first cleaning gas is 0.05,and decreased by about 30% to about 40% as compared with the values whenthe second cleaning gases are not added.

[0072] Sixth Embodiment

[0073] C₄F₈ is used as the fluorocarbon gas of the first cleaning gas,and N₂, NO, or N₂O is used as the second cleaning gas. C₄F₈ of about 100sccm and O₂ of about 400 sccm are supplied. When the second cleaning gasis not added, the cleaning rate is about 232.9 nm/min, and the DRE andthe MMTCE are about 99% and about 6.15×1 0-11, respectively.

[0074] In the case of N₂, the cleaning rate is highest at the additionof 0.15 N₂ to C₄F₈/O₂, and is about 333.6 nm/min. In the case of NO, thecleaning rate is highest at the addition of 0.15 NO to C₄F₈/O₂, and isabout 314.5 nm/min. In the case of N₂O, the cleaning rate is highest atthe addition of 0.15 N₂O to C₄F₈/O₂, and is about 307.5 nm/min.

[0075] The DREs are about 99% without regard to additions and kinds ofthe second cleaning gas.

[0076] The additions of the second cleaning gases, N₂, NO and N₂O, toC₄F₈/O₂ decrease the MMTCEs. The MMTCEs are lowest when the secondcleaning gas is added at the flow rate of 0.15 to the first cleaninggas, and decreased by about 25% to about 40% as compared with the valueswhen the second cleaning gases are not added.

[0077] Comparison

[0078] To compare the results from the embodiments of the presentinvention, another cleaning process using NF₃ as a cleaning gas isperformed in the same conditions and the same apparatus as the firstembodiment. At this time, argon gas (Ar) is added to NF₃. The flow ofNF₃ is about 20 sccm and the flow rate of Ar mixed to NF₃ is varied.

[0079] The additions of Ar to NF₃ initially increase the cleaning rate,and the highest cleaning rate is about 310 nm/min at the flow rate of0.5 Ar to NF₃. Also, the differences in the cleaning rates among thethree locations, that is, at the center of the substrate holder, at theside wall of the chamber, and at the front wall of the chamber, are lessthan 10%, thereby showing uniform cleaning rates regardless of location.

[0080] The DREs are over 99% without regard to additions of Ar, therebyshowing that most of fed NF₃ gas is destructed.

[0081] Also, the MMTCEs are about 0.5×10⁻¹⁰ without regard to additionsof Ar. Meanwhile, the MMTCEs normalized to 1,000 nm/min of the cleaningrate for silicon nitride are within a range of about 10.0×10⁻¹⁰ to about12.5×10⁻¹⁰.

[0082] As mentioned above, the cleaning method of the present inventiondecreases global warming gases released after cleaning process, and thusreduces global warming effect.

[0083] The cleaning method of the present invention increases cleaningrates, thereby improving processing efficiency, and the chamber isuniformly cleaned by the cleaning method of the present invention.

[0084] In addition, since the cleaning gas used in the present inventionis cheaper than NF₃, the manufacturing costs of the semiconductor deviceare decreased.

[0085] It will be apparent to those skilled in the art that variousmodifications and variations can be made in the fabrication andapplication of the present invention without departing from the spiritor scope of the invention. Thus, it is intended that the presentinvention cover the modifications and variations of this inventionprovided they come within the scope of the appended claims and theirequivalents.

What is claimed is:
 1. A cleaning method of an apparatus formanufacturing a semiconductor device, comprising: providing a firstcleaning gas and a second cleaning gas into a chamber, and forming amixture of the first cleaning gas and the second cleaning gas, the firstcleaning gas including a fluorocarbon gas and an oxygen gas, the secondcleaning gas including nitrogen; activating the mixture of the firstcleaning gas and the second cleaning gas by a high frequency power; andexhausting residues cleaned by the activated mixture and remaininggases.
 2. The method according to claim 1, wherein the fluorocarbon gasis one of C₃F₈, C₄F₈ and C₄F₈₀.
 3. The method according to claim 1,wherein the second cleaning gas includes one of N₂, N₂O and NO.
 4. Themethod according to claim 1, wherein a flow rate of the fluorocarbon gasto the oxygen gas is within a range of 0.1 to 0.5.
 5. The methodaccording to claim 1, wherein a flow rate of the second cleaning gas tothe first cleaning gas is within a range of 0.01 to 0.5.
 6. The methodaccording to claim 1, wherein the mixture of the first cleaning gas andthe second cleaning gas is activated in a plasma generator outside thechamber.
 7. The method according to claim 1, wherein the mixture of thefirst cleaning gas and the second cleaning gas cleans silicon, siliconnitride and silicon oxide in the chamber.
 8. A cleaning method of anapparatus for manufacturing a semiconductor device, comprising:activating a first cleaning gas by a high frequency power, the firstcleaning gas including a fluorocarbon gas and an oxygen gas; activatinga second cleaning gas by a high frequency power, the second cleaning gasincluding nitrogen; mixing the activated first cleaning gas and theactivated second cleaning gas, thereby forming a mixture of the firstcleaning gas and the second cleaning gas; and exhausting residuescleaned by the mixtuer and remaining gases.
 9. The method according toclaim 8, wherein the fluorocarbon gas is one of C₃F₈, C₄F₈ and C₄F₈₀.10. The method according to claim 8, wherein the second cleaning gasincludes one of N₂, N₂O and NO.
 11. The method according to claim 8,wherein a flow rate of the fluorocarbon gas to the oxygen gas is withina range of 0.1 to 0.5.
 12. The method according to claim 8, wherein aflow rate of the second cleaning gas to the first cleaning gas is withina range of 0.01 to 0.5.
 13. The method according to claim 8, wherein themixture of the first cleaning gas and the second cleaning gas cleanssilicon, silicon nitride and silicon oxide in the chamber.